Field
The present disclosure relates generally to the synthesis and fabrication of nanomaterials and nanocomposites, and more particularly to the synthesis of nanowires, whiskers, elongated nanomaterials, porous elongated nanomaterials, and the like, and their use in polymer, ceramic, glass, and metal composites, as well as in catalysts, energy storage devices, membranes/separators, filters, optical devices, and other applications.
Background
Owing in part to their relatively light weight, high surface area, and good mechanical properties, elongated ceramic materials with a diameter less than around 10 microns down to a few nanometers, a length from around 10 nm to around 1 mm, an aspect ratio from around 4 to around 20,000, and specific surface area in the range from around 2 to around 3,000 m2/g may be utilized in a broad range of composites and nanocomposites for enhancement of various mechanical properties, optical properties, thermal stabilities, and other properties. The production of such materials, often called ceramic nanowires, nanofibers, or whiskers (depending on their dimensions and morphology), with controlled dimensions and at a low cost would be desirable for a wide range of composite applications as reinforcement. Thermally stable nanowires and whiskers may be particularly attractive in high temperature applications. In contrast to carbon nanotubes and carbon (nano)fibers (other types of elongated nanomaterials made primarily of carbon atoms), ceramic nanowires may offer improved dispersion, optical transparency, stability against oxidation at elevated temperatures, electrical insulation, more easily modifiable surfaces, and other properties, which make them attractive for various applications.
However, despite the useful properties and the commercial potential of ceramic nanowires, nanofibers, and whiskers, their applications have been rather limited due to the high cost of the conventionally-employed synthesis techniques (such as chemical vapor deposition, hydrothermal synthesis, and others) and the limited experimental ability to tune their characteristic dimensions, surface morphology, and other properties.
Accordingly, there remains a need for improved methods for synthesis of ceramic nanowires, nanofibers, whiskers, and other related materials, as well as their modification and use in composites. There additionally remains a need for improved materials and improved manufacturing processes.